U.S. patent application number 12/774857 was filed with the patent office on 2011-11-10 for linear motor system for an exercise machine.
Invention is credited to Mark Greenhill, Michael Greenhill, Brand Hill.
Application Number | 20110275481 12/774857 |
Document ID | / |
Family ID | 44902307 |
Filed Date | 2011-11-10 |
United States Patent
Application |
20110275481 |
Kind Code |
A1 |
Greenhill; Michael ; et
al. |
November 10, 2011 |
LINEAR MOTOR SYSTEM FOR AN EXERCISE MACHINE
Abstract
Exercise machines and linear motor systems for use in exercise
machines are provided herein, where the linear motor provides a
resistance force in response to a force generated by a user
performing an exercise. The linear motor systems include a
programmable logic and force generation control system, which is
programmable to control the resistance provided by the linear
motor.
Inventors: |
Greenhill; Michael;
(Highland Park, IL) ; Greenhill; Mark; (Winnetka,
IL) ; Hill; Brand; (Glenview, IL) |
Family ID: |
44902307 |
Appl. No.: |
12/774857 |
Filed: |
May 6, 2010 |
Current U.S.
Class: |
482/5 ;
482/92 |
Current CPC
Class: |
A63B 21/0058
20130101 |
Class at
Publication: |
482/5 ;
482/92 |
International
Class: |
A63B 21/005 20060101
A63B021/005; A63B 21/00 20060101 A63B021/00 |
Claims
1. An exercise machine that comprises: a linear motor system having
a linear motor including a forcer that moves along a magnetic
shaft, wherein the linear motor acts as a force producing element
to provide resistance to a force generated by a user when
performing an exercise.
2. The exercise machine of claim 1, wherein the linear motor system
further comprises: a base; a header support; and a pair of linear
shafts that extend from the base to the header support, the forcer
being slidably attached to the linear shafts, and the magnetic
shaft being located between the linear shafts and extending from
the base to the header support.
3. The exercise machine of claim 1, wherein the linear motor system
further comprises a programmable logic and force generation control
system operatively connected to the linear motor system, the
programmable logic and force generation control system comprising a
microprocessor that is programmable to control the resistance
provided by the linear motor.
4. The exercise machine of claim 1, wherein the resistance provided
by the linear motor can be varied in increments of about 0.5 pounds
or greater.
5. The exercise machine of claim 1, wherein the resistance provided
by the linear motor can be provided in a positive direction or a
negative direction.
6. The exercise machine of claim 1, wherein the linear motor is a
servo motor.
7. The exercise machine of claim 1, wherein the forcer is linearly
displaced in response to the force generated by a user when
performing an exercise.
8. The exercise machine of claim 7, wherein the forcer starts at a
home position when the user is in an initial position for
performing the exercise, rises vertically to a stroke displacement
as the user reaches a full stroke of the exercise, and returns to
the home position as the user finishes the exercise by returning to
the initial position.
9. The exercise machine of claim 1, wherein the forcer is
mechanically connected to a handle to which the user applies force
while performing the exercise.
10. The exercise machine of claim 9, wherein the forcer is
connected to the handle by cables and pulleys.
11. A linear motor system for producing a resistance force in an
exercise machine in response to a force generated by a user when
performing an exercise, the linear motor system comprising: a base;
a header support; a pair of linear shafts that extend from the base
to the header support; a magnetic shaft located between the linear
shafts and extending from the base to the header support; and a
forcer slidably attached to the linear shafts that moves along the
magnetic shaft to produce the resistance force.
12. The linear motor system of claim 11, wherein the linear motor
system further comprises a programmable logic and force generation
control system operatively connected to the linear motor system,
the programmable logic and force generation control system
comprising a microprocessor that is programmable to control the
resistance provided by the linear motor.
13. The linear motor system of claim 11, wherein the programmable
logic and force generation control system further comprises: a user
interface; and a linear position feedback sensor to allow control
of the linear position and velocity of the forcer.
14. The linear motor system of claim 13, wherein the user interface
comprises graphical user interface.
15. The linear motor system of claim 13, wherein the user interface
comprises an interactive interface configured to allow the user to
input data to program an exercise routine.
16. The linear motor system of claim 15, wherein the interactive
interface comprises at last one of a touch screen, a keypad, or a
data transfer link.
17. The exercise machine of claim 11, wherein the resistance force
provided by the linear motor can be provided in a positive
direction or a negative direction.
18. The exercise machine of claim 11, wherein the linear motor is a
servo motor.
19. The exercise machine of claim 11, wherein the forcer starts at
a home position when the user is in an initial position for
performing the exercise, rises vertically to a stroke displacement
as the user reaches a full stroke of the exercise, and returns to
the home position as the user finishes the exercise by returning to
the initial position.
20. A linear motor system for producing a resistance force in an
exercise machine in response to a force generated by a user when
performing an exercise, the linear motor system comprising: a base;
a header support; a pair of linear shafts that extend from the base
to the header support; a magnetic shaft located between the linear
shafts and extending from the base to the header support; a forcer
slidably attached to the linear shafts that moves along the
magnetic shaft to produce the resistance force; and a programmable
logic and force generation control system operatively connected to
the linear motor system, the programmable logic and force
generation control system comprising a microprocessor that is
programmable to control the resistance provided by the linear
motor.
Description
BACKGROUND
[0001] The present technology relates to an exercise machine that
utilizes a linear motor to provide resistance to a force generated
by a user performing an exercise, and to linear motor systems for
use in such exercise machines..
[0002] Typical physical fitness training equipment utilizes a
weight stack sliding on vertical rods under the influence of
gravity as the force producing element. Movement of the weight
stack by the user is caused by tension created in a cable that
attaches to the top of the weight stack. The weight stack, and more
specifically gravity acting on the weight stack, is the force
producing element that provides resistance to a pulling force
generated by the user during an exercise routine. The weight stack
is movable vertically through a series of pulleys and levers
utilizing hand grips, bars, or other types of user devices to
perform an exercise by lifting the weight stack. For example, FIG.
1 illustrates a known example of an exercise machine 100, with
which a user can perform a number of exercises using a weight stack
114. The weight stack 114 slides along two parallel vertical rods
106 and 108 when the user of the exercise machine 100 pulls on the
cable 120 during the course of performing an exercise routine. The
vertical rods 106 and 108 are secured to the exercise machine 100
by a bottom weight support rod bracket 116 and a top weight support
rod bracket 104. An attachment bolt 102 is used to secure the top
weight support rod bracket 104 to the frame of the exercise machine
100. The cable 120 is connected at one end to a cable attachment
bolt 110 which serves to secure: the cable 120 to a weight support
assembly 118 which is part of the weight stack 114. A weight
selection pin 112 may be inserted into one of a plurality of holes
in the weight stack 114, in order to select the amount of weight in
the stack which will be moved during the performance of the
exercise routine by the user. The other end of the cable 120, after
passing through various pulleys, may be connected to various
attachments (not shown) for use in performing the selected
exercise, all in a known manner.
[0003] Other non-electronic weight lifting systems have also been
utilized by designers of weight lifting equipment that offer
variable resistance or fixed weight. In one example, large rubber
bands have been utilized to produce resistance. In another example,
hydraulic and/or pneumatic cylinders have been designed into weight
lifting machines to produce resistance. Multiple weight stacks have
also been incorporated into weight lifting equipment whereby
additional weight can be added in a routine as the routine
progressed by having the first weight stack come in contact with a
secondary weight stack as the exercise progresses, adding
predetermined weight during the routine.
BRIEF SUMMARY
[0004] The linear motor systems and exercise machines disclosed
herein utilize a linear motor to provide resistance to a force
generated by a user performing an exercise.
[0005] In one aspect,.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0006] Specific examples have been chosen for purposes of
illustration and description, and are shown in the accompanying
drawings, forming a part of the specification.
[0007] FIG. 1 illustrates an exercise machine of the prior art that
includes a weight stack.
[0008] FIG. 2 illustrates one example of an exercise machine of the
present technology, having a linear motor system.
[0009] FIG. 3 illustrates a front view the linear motor and linear
motor support structure of the example of FIG. 2.
[0010] FIG. 4 illustrates a top view of the linear motor and linear
motor support structure of the example of FIGS. 2 and 3.
[0011] FIG. 5 illustrates a diagram of a control system for the
exercise machine of FIGS. 2-4.
[0012] FIG. 6 illustrates one example of a user interface for an
exercise machine of FIGS. 2-4, in which the user can select a
standard curve to control the exercise routine.
[0013] FIG. 7 illustrates one example of a user interface for an
exercise machine of FIGS. 2-4, in which the user can input a custom
curve to control the exercise routine.
[0014] FIG. 8 illustrates a force versus distance graph of the
operation of the exercise machine of FIG. 2 in a fail safe
mode.
DETAILED DESCRIPTION
[0015] The apparatus and system disclosed herein provides a
replacement for the dead weight stack in any type of weight lifting
equipment. Specifically, weight lifting equipment is disclosed
herein that includes a linear motor system instead of a weight
stack. The linear motor system includes a linear motor that acts as
a force producing element to provide resistance to a force
generated by a user when performing an exercise during an exercise
routine. Exercise machines that incorporate linear motor systems of
the present technology can be utilized in activities including, but
not limited to, muscle building, strength training, endurance
training, rehabilitation, and any other physical fitness
application. For example, FIG. 2 illustrates an exercise machine
100 that is similar to the exercise machine of FIG. 1, but in which
a linear motor system 200 of the present technology has been
utilized instead of a weight stack. It should be noted that
although only one linear motor is illustrated in FIG. 2,
alternative exercise machines of the present technology can utilize
two or more linear motors.
[0016] Linear motors as utilized herein generally include two
magnetic fields that interact to induce or produce a force vector.
The first magnetic field can be stationary, and the second magnetic
field can move linearly along a path of travel defined by the first
magnetic field. For example, referring to FIGS. 2 through 5, the
linear motor system 200 includes a linear motor 202 that has a
magnetic shaft 204 and a forcer 206 that can be moved along the
magnetic shaft 204 in response to a force generated by a user
during an exercise routine. The magnetic shaft 204 produces the
first magnetic field, and can include a plurality of permanent
magnets that are spaced along the path of travel. The plurality of
permanent magnets are preferably equally spaced along the entire
length of the path of travel, The forcer 206 produces the second
magnetic field, which can be an electro-magnetic field. The forcer
206 includes a plurality of electric coils that are electrically
isolated from one another, and that can be bonded together as a
single unit. In some examples, the forcer 206 can include a
plurality of groups of electric coils that are electrically
connected together, and can be excited together, which can
substantially increase the surface-area of
electro-magnetic-to-magnetic field interaction, and subsequently
the linear force which can be generated.
[0017] The electro-magnetic field produced by the forcer 206 can be
variable with respect to magnitude, and can be switchable, meaning
that it can be generated in any one or more of the electric coils
contained within the forcer. A drive, such as a servo drive, can be
utilized to control the magnitude of the electro-magnetic field
magnitude and sequence the position of the electro-magnetic field
between the coils in the forcer 206, in order to produce a linear
force when the forcer 206 is in fixed proximity to the stationary
magnetic field of the magnetic shaft 204. When the electro-magnetic
field produced by the forcer 206 is de-energized, the linear motor
202 will not produce any linear force. Thus, when the forcer 206 is
de-energized, the linear motor system 200 will not provide any
resistance to the force generated by the user utilizing the
exercise machine, other than the actual physical weight of the
forcer 206, the bearings 214 and the brackets 216 that are
discussed below.
[0018] A linear motor system 200 can also include a support
structure for the linear motor 202 that has a base 208, a header
support 210, and a pair of linear shafts 212 that extend from the
base 208 to the header support 210. In the illustrated example, the
base 208 and header support 210 can be horizontal, or substantially
horizontal, and the linear shafts 212 can be vertical or
substantially vertical. The linear shafts 212 are spaced apart, and
are preferably parallel or substantially parallel. The linear
shafts 212 can be connected to the base 208 and the header support
210 in any suitable manner. The linear shafts 212 can be made of
any suitable material, and are preferably made of hardened
steel.
[0019] The magnetic shaft 204 can be located between the linear
shafts 212 and can extend from the base 208 to the header support
210. The magnetic shaft 204 can be connected to the base 208 and
the header support 210 in any suitable manner. In the illustrated
example, the magnetic shaft 204 can be vertical, or substantially
vertical. The magnetic shaft 204 is preferably centrally located
between the linear shafts 212, so that the distance between the
center of the magnetic shaft and the center of either linear shaft
212 is equal or substantially equal.
[0020] The forcer 206 can be slidably connected to the linear
shafts 212, and can be linearly displaced along the magnetic shaft
204 when a user applies force in performing an exercise. In the
illustrated example, the forcer can be linearly displaced in a
vertical direction, wherein the forcer 206 can start at a home
position or lowered position when the user is in an initial
position for performing the exercise, then rise vertically to a
stroke displacement as the user reaches the full stroke of the
exercise, and finally return to the home position as the user
finishes the exercise by returning to the initial position.
[0021] The forcer 206 can be attached to bearings 214 by brackets
216, and the bearings 214 can be slidably attached to the linear
shafts 212. The bearings 214 can slide up and down along the linear
shafts 212, and preferably slide with little friction or
essentially no friction. Referring to FIGS. 2 through 5, the forcer
206 can be mechanically connected to a handle 226, such as a bar or
other type of grip, to which the user 228 applies force while
performing an exercise, thus generating a pulling force on the
forcer 206 of the linear motor 202. For example, two pulleys 218,
one located on each side of the magnetic shaft 204, can be attached
to the linear motor system 200 at or near the top of the magnetic
shaft 204. Two cables 220 can be secured to the forcer 206, with
one cable 220 being connected to the forcer 206 on each side of the
of the magnetic shaft 204. The cables 220 can each engage one of
the pulleys 218, and can connect to a single pulling cable 222 at a
cable connecting point 224 located above the two pulleys 218. The
pulling cable 222 can be operatively connected to the handle 226,
and can engage one or more pulleys 230 that are intermediately
located between the handle 226 and the connecting point 224. The
cables 220 and 222 can be made of any suitable materials, and are
preferably steel cables.
[0022] In some examples, mechanical adjustments can be incorporated
to increase or decrease the force generated by the linear motor
system 200. For example, a motor to user pulley size ratio of 1.5:1
within the exercise machine would increase the weight resistance
out of the linear motor system 200 by 50% as compared to a motor to
user pulley size ratio of 1:1. Conversely, a motor to user pulley
size ratio of 1:1.5 within the exercise machine would decrease the
weight resistance of the linear motor system 200 by 50% as compared
to a motor to user pulley size ratio of 1:1.
[0023] Referring to FIG. 5, the linear motor system 200 can include
a programmable logic and force generation control system 300 that
is operatively connected to the linear motor 202 and to a user
interface 302. The programmable logic and force generation control
system 300 can determine the state of the system by measuring the
force, velocity, linear displacement, and direction of linear
actuation, during the exercise routine. As shown in FIG. 5, the
programmable logic and force generation control system 300 can
include a user interface 302 operatively connected to a
microprocessor 304 that is programmable to control the resistance
provided by the linear motor 202, a servo amplifier 306 operatively
connected to the microprocessor 304 and the forcer 206, one or more
positive limit sensors 308 operatively connected to the
microprocessor 304, one or more negative limit sensors 310
operatively connected to the microprocessor 304, and a power supply
312 that can provide power to any components of the exercise
machine 200 as necessary. As illustrated in FIG. 5, the
microprocessor 304, servo amplifier 306 and power supply 312 can be
housed in a control panel 314.
[0024] The microprocessor 304 can receive data from the servo
amplifier 306, the user interface 302, the one or more positive
limit sensors 308, and the one or more negative limit sensors 310.
The servo amplifier 306 can receive data from and send data to both
the microprocessor 304 and the forcer 206, and can control the
linear position and velocity of the forcer 206. The microprocessor
304 can execute a program that includes a set of instructions that
enable the microprocessor to acquire data, compare values, and
execute operations. For example, the microprocessor 304 can acquire
data such as the position of the forcer 206 along the magnetic
shaft 204, and the current. Microprocessor 304 can compare the
acquired data to values that are calculated or user-defined, and
can execute corrective actions to command and control both the
magnitude and position of the electro-magnetic field produced by
the forcer 206, and hence the force generation of the linear motor
202. In this manner, the microprocessor 304 can control the
magnitude of the electromagnetic field, with respect to the
position of the forcer 206, in order to increase, decrease, or
maintain as constant the linear force generated by the interaction
of the two magnetic fields.
[0025] The one or more positive limit sensors 308, and the one or
more negative limit sensors 310 can be positioned to detect the
presence of the forcer 206 at locations at or near the endpoints of
the magnetic shaft 204. When the presence of the forcer 206 is
detected by any of the positive or negative limit sensors 308 and
310, the sensor can send a signal to the microprocessor 304
indicating the presence of the forcer, and the microprocessor 304
can send appropriate command data to control the position of the
forcer 206. In one preferred example, each of the one or more
positive limit sensors 308 and the one or more negative limit
sensors 310 the linear position feedback sensor can have a 25
micron resolution and can be analog in nature, allowing the sensor
to continuously supply data as quickly as the microprocessor 304
can sample data.
[0026] The user interface 302 of the of the programmable logic and
force generation control system 300 can be operatively connected to
the microprocessor in any suitable manner, including, but not
limited to an ethernet connection or a wired connection. The user
interface 302 can include any suitable graphical user interface
316, and can also include an interactive interface 318 configured
to allow the user to input data to program an exercise routine. The
interactive interface 318 can be separate from or incorporated into
the graphical user interface 316, and can, for example, include at
least one of a touch screen, a keypad, or a data transfer link to
input the data. In examples utilizing a touch screen and/or a
keypad, the user can directly input the data to program an exercise
routine. In examples utilizing a data transfer link, the user can
transfer data from a computer readable storage medium in order to
program the programmable logic and force generation control system
300. Examples of suitable data transfer links include, but are not
limited to, wireless connections, as well as parallel ports or
serial ports. In one example, an interactive interface 318 can
include a USB port, and a user can transfer an exercise routine
program to the programmable logic and force generation control
system 300 from a USB flash memory stick. In other examples, a user
can transfer data programmable logic and force generation control
system 300 from a personal computer or from a handheld computing
device such as an iPod.TM..
[0027] Utilization of the programmable logic and force generation
control system 300 can allow the linear motor system 200 to be
programmable to provide resistance in both positive and negative
directions during an exercise cycle. The positive direction is the
direction of the exercise stroke, which is the first half of the
exercise cycle as the user goes from an initial position to a
stroke position such as, for example, an extended position. The
negative direction is the direction of the return, which is the
second half of the exercise cycle in which the user returns to the
original position ready to begin another stroke. Further, the
utilization of the programmable logic and force generation control
system 300 can allow the linear motor system 200 to be infinitely
programmable to permit the user to define his or her own weight
lifting routine in simple or complex curves.
[0028] FIG. 6 illustrates one example of a screen display 400 for
the user interface of a programmable logic and force generation
control system 300 of the present technology, which provides a
visual selection 402 of standard exercise routine curves and
permits a user to select an exercise routine curve at a first
indicator location 404, as well as permitting the user to enter a.
minimum load value at a second indicator location 406 and a maximum
load value at a third indicator location 408, prior to beginning
the exercise routine. A standard exercise routine curve can be a
curve that is pre-programmed and stored in the programmable logic
and force generation control system 300. When a standard exercise
routine curve is selected by the user, it can be utilized by the
programmable logic and force generation control system 300 to
control the amount of resistance, or the load, that will be
produced by the linear motor system 200 during each stroke of the
exercise routine. The exercise routine curve selected by the user
can be as simple as straight line, as shown in Mode 1, which
provides a pre-specified constant force in both the positive
direction and the negative direction. Alternatively, the exercise
routine curve can provide as many resistive load changes as desired
within a single stroke of the exercise machine. Some examples of
such exercise routine curves are illustrated in Modes 2 through 6
of FIG. 6. The screen display 400 can also include a routine
monitor 410 that displays information measured by the programmable
logic and force generation control system 300 during performance of
the exercise routine by the user.
[0029] FIG. 7 illustrates an example of a screen display 500 for
the user interface of a programmable logic and force generation
control system 300 of the present technology, which provides a
visual display of a custom exercise routine curve that can be
entered by a user. The illustrated custom curve includes a
plurality of programmable regions to provide the user with the
ability to pre-define the weight, velocity and/or direction of the
exercise routine. As illustrated, the custom curve can be setup to
divide the motion of the exercise into four distinct (4) regions;
two (2) regions for the first half of the motion, such as the full
stroke or extension, and two (2) regions for the second half of the
motion, such as the return stroke back to the original position.
Each region of the custom curve can be defined according to user
defined parameters including the amount of weight, the amount of
weight change, and the type of weight change. Types of weight
change that can be selected include, for example, constant weight,
linear increase, exponential increase, linear decrease, and
exponential decrease.
[0030] In practice, the exercise machine can be calibrated prior to
the start of any exercise routine. During calibration the
programmable logic and force generation control system can monitor
and learn the amount of linear displacement necessary for a given
individual or exercise. In order to calibrate the system for a
particular routine, the user would initiate a calibration mode by
selecting that mode at the user interface, such as by pressing the
"Calibrate Stroke" box on the touch screen display of FIG. 6 or
FIG. 7. In the calibration mode, the linear motor would apply a
very low resistance force. The user can assume an initial position
for the exercise, grip the handle or bar of the exercise machine,
and then perform the desired motion for the full stroke of the
exercise, which is half or 50% of the full motion for the exercise.
Performance of the stroke of the exercise can result in a
displacement of the linear motor along it's length of travel,
starting at a home position when the user is in the initial
position for the exercise and moving to a stroke displacement when
the user performs the stroke of the exercise. The programmable
logic and force generation control system can monitor and record
the position of the linear motor, and can record the stroke
displacement, which is the maximum distance of travel for the
linear motor during the given exercise. Assuming that the user
performs the stroke of the exercise in a similar manner each time,
as should be done for proper form, then the stroke displacement is
a turn-around point for the linear motor. In one example, the
stroke displacement can be identified and noted by the programmable
logic and force generation control system as being the point at
which the displacement of the linear motor remains unchanged for 1
second. The user would then reverse the motion of the stroke for
the exercise, returning to the initial position, and thus returning
the linear motor to home position, simulating a complete exercise
cycle. Once the stroke displacement has been identified by the
programmable logic and force generation control system, the
programmable logic and force generation control system can apply
the resistance profile selected by the user across the correct
linear distance. For example, stroke displacement in the example of
FIG. 6 was identified as being 4 feet during calibration.
Accordingly, the routine monitor 410 in FIG. 6 shows a full stroke
distance of 4 feet at point "A."
[0031] Exercise machines of the present technology can include a
safety setting, or fail safe mode of operation, that can operate if
the programmable logic and force generation control system detects
a no load situation. A no load situation can be detected when there
is a load change or velocity change, such as a high linear
acceleration or no resistance, as would happen in instances where a
user lets go of the handle. FIG. 8 illustrates a graph of the
amount of weight versus the distance traveled for a fail safe mode
of operation. As illustrated, the user begins the exercise and lets
go of the handle at point "X," which is at less than 25% of the
complete cycle and a resistance force of 61 pounds. The
programmable logic and force generation control system detects the
no load situation and begins a reverse mode, wherein it rapidly
reduces the resistive force of the linear motor from 61 pounds to
about 10 pounds, and then gradually tapers the amount of weight
down to zero as the position of the linear motor returns to home
position. The fail safe mode can be operated to prevent anyone from
getting injured during an exercise routine.
[0032] From the foregoing, it will be appreciated that although
specific examples have been described herein for purposes of
illustration, various modifications may be made without deviating
from the spirit or scope of this disclosure. It is therefore
intended that the foregoing detailed description be regarded as
illustrative rather than limiting, and that it be understood that
it is the following claims, including all equivalents, that are
intended to particularly point out and distinctly claim the claimed
subject matter.
* * * * *